Rotary siren



ROTARY SIREN Filed Oct. 7, 1948 SIREN ROTO/K7 S/RE/V 5T -L/Ql// LEVEL PUMP HOUSING PUMP /MPELLE/z Patented Nov. 4, 1952 s PATENT ortica ROTARY SIREN Ernest Stuart Russell, Wraysbury, EnglandV .Application October 7, 1948,`Serial No. 53,173

In Great Britain January 22, 1948 j 2 Claims. (Cl. 177-7) h VThis invention is designed tov facilitate the operation of sirens of the rotary type.. Such sirens commonly have a rotor with substantially radial blades and a ported rim so arranged vas to vcreate by centrifugal force a pressure ofA air and distinct signals or signals of short duration.

f This .difiicultyhas been partially overcome in .sirens constructed `by the applicant in whichthe air intake of ,av standard siren istted witha mechanically or electrically operated valve or shutter. e Y By allowing the siren to rotate continuously whilst the shutter `.is opened and closed in -a prearranged time sequence it is `possible to obtain distinctive signals. Shuttersv on the discharge side of the statorhave also been tried.

It has also .been proposed in United States Patent N o. 2,535,520, granted to me December 26, V1950, to fit a cover which envelops both the suction and discharge portions of the siren so as to prevent ingress of air from and egress to outside the cover when this is pressed against a flange for the equivalent on the sirenstator. Such la cover may be'arranged to obstruct entirely the inlet to the rotor when the cover is sealed on' to the stator so'as to prevent any internal circula-I furnishing and applying the necessary power to` operate rotary'sirens-of all the above mentioned and similar types in a convenient manner which combines ease and speed ofoperation with moderate cost andwithout the necessity for undue occupation of space by the operating mechanism.

This is accomplished by connecting the shutter or cover to fluid pressure operated actuating means and utilising the motor which drives the siren rotor also to drive means for supplying fluid under pressure to the actuation means. l a. Y

Accordingly, one important feature of the invention lies in the application of fluid' pressure to actuate the operating means of such sirens, irrespective of the source from which the pressure fluid is derived, though it will often be' contion of air except thatwithin the actual stator.

Further, the rotor shaft may bel made hollow so that' anoperating rod supported on external bearings may pass through it without touching it. This rod is used to apply manual or electromagnetic pressure to the cover,'to open or close it. Y 1

For the purpose of operating the shutters, valves or covers of rotary sirens, ithas been the usual practice to employ direct manual power by means of a system of levers operated by a lanyard, or an electromagnet. ,In the case of sirens requiring any considerable effort to open or close the yshutteror cover it has been found'i'nconvenientto use manual power and the size and cost of an electromagnet capable of exerting the necessary power have been so'great as to make thissystem undesirable. l

'I'he present invention provides venient to drivea pressure pump or the equivalent from the motorwhich drives the siren and so make the apparatus substantially selfcontained. When the siren is driven electrically it is also often convenient to control electrically the application of the-pressure to the actuating means.

An important part of the invention lies in the control of the actuating means by two pressure relief devices, zone becoming operative automatically when `a given movement of the siren controlling means is exceeded, so limiting the travel of the siren operating valve, shutter, cover or the like, and the other being valve means closable against the pressure of the uid to cause its application to the actuating means and consequent initiation of a soundrsignal and openable to relieve the pressure (by exhaust to atmosphere bypassing or otherwise) and so to cause the signal to be cut off. The valve means may take the form of an electrically (conveniently solenoid) operated valve, enabling push button or similar simple electrical control of the whole apparatus to be used. Y

The invention thus embodies several parts or aspects, those for vwhich patent protection is desired being embodied in the apparatus hereinafter described and delimited by the claims.

Al typicalform of the invention is shown by way of example by the accompanying drawing which is acentral vertical section of any electrically. driven siren'using a cover to control the initiation and cutting off of signals.v

The outer case I contains an electric 'motor consisting `of field yoke 2 and rotor 3 Ymounted upon bearing assemblies 4 and 5. `Hollow Vshaft 6 carries soundlrotor 'I running in stator 8. The cover 9fhaving 1a rbush l0 is slidably mounted upon pillar H Vwhich formsV part of stator'cover l2 containing the suction intake which isnormallyv clo'sedfby valvev disc'l3. Vi The opening and 3 closing of the cover 9 and valve disc I3 to enable the giving of sharp and distinct signals as described in the United States Patent No. 2,535,520 is accomplished by the Vertical movement of push rod I4. 'Ihe upward movement of this rod is made by fluid pressure displacing piston I in cylinder fIE. `A hollow shaft 21 vcarries a centrifugal pump impeller I'I at its lower extremity. This impeller running within the pump casing I3 draws oil or other liquid (the liquid level in the fluid reservoir 29 formed by the bottom .of the outer case I being indicated at 28) through the suction intake I9 and discharges it under pressure through a discharge oriiice Il andgpipe 2I leading to the lower part of cylinder 16. valve 22 which can be held closed by the energising of electro-magnet 23 which holds armature 24 against valve 22 will prevent the escape of 2the oil and -will allow a'pressure to build up in thecylinderwhilst rotor V3 is turning. This pressure "will cause piston I5 to rise and this Vin Vits 'turn will "cause'cover 9 'and '-valve VI3 to open by means of =pushrod I4. -Wheneover 9 has-reached vthe limit of its desirable istroke, piston I5 will 'start touncover vexhaustlports '25 and there will be lableeding ofthepressure 4so as -to establish an equilibrium Ybetween 'the .pressure applied to :piston I5 and-'the gravity 4'and suction -pulls upon cover 9 tending Ito-oppose this pressure Y When itis `desiredto close cover 9and valve -I3 theelectrical circuit-supplying electromagnet applied -tofpiston I5 Vis insufficient to support the cover' 'which closes rapidly under the inuence of thegravity and suctionpulls.

VAI

`Kids-opened. This allows the fluid pressure to lopen valve`22 with fthe-result that the pressure quenceof-sharp 'and distinct -signals by opening and-closing the electrical-circuit'to electromagne'rl The A:following considerations `may Vbe helpful Y v to 1-a lproper understanding of the lnature and meritsfo'f the invention. IInorder to makepush bulttonor like operation of the means for actuating the coverior other signal control means'of fthe siren, Velectro-magnetic devices are suitable fonlyfor relatively-smallsirens. In trying to defvis'e means toutilize a rotary movement, pref- =erablyvthepowerof the electricmotor of the siren, it appeared necessary -to fintroduce between the "electricmotor shaft andthe-cover such aseries of reduction gears, `clutches, cams and the'like, `as tomakethe whole `apparatus costly to manufacture, difficult .to maintain, and eminently unre- 'liable infservice. The same thing vapplied to the Iinstantaneous releasing of the cover lupon the releasing of the operating push button. r`fUse of electromagnets permissible in very small sizes 'of sirens, .but whenanyflarge amount of power -isz-to be exerted thesefb'ecome Vtoo y large and take too 4much power. `fIh'e .dissipation iof Afthe heat from these also becomes a great-problem. It

Number `mension of the-airf gap `.and .that initial closing speed is veryzslow,"whereasin the 'case Aof sirens, and 'particularlyf`marine isiren's, itis the initial movement which should be quick in order that in times of danger a sound signal may be given quickly. The use of fluid pressure to raise the cover has provided the solution to all these problems and it has been found that even from a standing start the opening of the cover is almost instantaneous because the centrifugal pump can be designed to give a pressure suicient to raise the cover even when it is running at a low speed.

'When the cover has reached the limit of its stroke the pump is automatically unloaded by the bleeding through the holes 25.

Fundamentally, I have accomplished my object vwith asourceiofiluid pressure and only two mov- .ing parts-that is to say, the piston and the electrically operated relief valve, whereas with any mechanical apparatus I should have had to use anything up to ifty or sixty par-ts, and the apparatus `would in any case have 'been unsatisfactory.

The basic idea underlying `the'invention in its `broader -aspects from V:this -point fof view accordingly'requires in practice any form of pres- Vsure'relief device to limit the travel of the control-device; any form-of quickpressure applicaltion and instant relief -device -to initiate and terminate the signal; andany source of fluid pressure, whether a pump embodied in the siren casing, an external'pump assembly, fluid pressure from available containers or reservoirs, or any other appropriate source.

I claim:

l. A rotary siren of the type having a power driven rotor and including 4operating means to free and obturatethe air ilowlthrough the siren to initiate and. cut-oif-signals characterised by the provisionof a vfluid reservoir, la pressure cylinder and piston, apump-drawing iluid from the said lreservoir 'and supplying it -under pressure to the pressure cylinder, 'anactuating member-operatively connecting the said piston to actuate the means operating to freethe air flow through the vsiren'and initiatesig'nals,k valve means automatically relieving the 'pressure in the cylinder aftera given movement'of the piston and a control valve Aoperable Yto-maintain or 'relieve at will-the workingpressure inthe said cylinder.

2. Avrotary siren'includingmovable obturators which rree'and -obturateithe'flow of air through the'siren,'fi1.ii`d 'pressure ,operable Vmeans `operatively 'connefcted "with v`said v'obturators Nto move themto free the airfow. sai'd fluidpressure operable means including a casing'having bleeder openings therein and a piston operable insaid casing,lsaidopenings bleeding the'fluid subject to apredetermined 'amount of movement of said piston, and Va .pressure relief ^valve `to Yrelieve the working pressure .and `enable the lobturators to return ,to .the position where thelairlflow .through thesirenis obturated. v

' .ERNEST-STUART RUSSELL.

REFERENCES CITED The :following :referencesare-y of :record in vthe iilefof-fthispatent':

1UNITED '2 STATES PATENTS Name l Date A1;213,'732 `Bossu Jan. p23, 1917 '1195'2,351 Armstrong vMar. A2.7, 41934: 1,985,954 Settegast Jan. 1, 1935 FOREIGN PATENTS Number Country `Date 560283 France July 4, 17923 

